The peptide bonds linking amino acids are very sturdy. Left alone, they'd last hundreds of years. In nature, proteases break them down, enzymes that evolution has tuned for countless jobs over millions of years.
What the researchers did
They took a shortcut. They kept the catalytic core of two kinds of protease and used AI protein design tools to replace everything else. The result is a set of enzymes that can be tuned to cut specific proteins in half.
Why it matters
The team tested the new enzymes on proteins linked to neurological diseases, and they worked. That points toward tools that remove harmful proteins precisely rather than in bulk.
What's still unknown
For now this is a lab demonstration of a method. Therapy is a long way off, but the core idea, that an enzyme for a chosen target can be designed from scratch, looks workable.